Core Specification: Dual-Layer Weld-Spatter Protection
Concentric dual-layer anti-spark tubing protects pneumatic lines in high-temperature welding cells. A UL94 V-0 flame-retardant outer jacket repels incandescent metal spatter, while the inner polyurethane (PU) core handles continuous working pressures of 10 to 13 bar (145 to 188 PSI).
5-Step One Touch Fitting Assembly Procedure
- Verify Dimensions: Verify tubing outer diameter (O.D.) matches fitting collet specifications.
- Cut Perpendicular: Cut the tube clean and square at 90°.
- Strip Outer Jacket: Strip to specified insertion depth (D) plus clearance tolerance (see table below).
- Seat Inner Core: Push the inner PU core firmly until bottomed out against the internal fitting stop.
- Lock & Pressure-Test: Pull back gently to verify internal collet retention, then run leak testing prior to line startup.
Insertion Depth (D) & Stripping Window (L)
- Nominal Stripping Length: L = D + 1.5 mm (0.06 in)
- Working Tolerance Window: D + 1.5 mm ≤ L ≤ D + 3.0 mm (D + 0.06 in ≤ L ≤ D + 0.12 in)
| Tubing Metric O.D. | Tubing Imperial O.D. | Standard Insertion Depth (D) | Mini Insertion Depth (D) |
|---|---|---|---|
| 3.0 mm | — | — | 10.5 mm (0.41 in) |
| 4.0 mm | 5/32" | 15.0 mm (0.59 in) | 11.5 mm (0.45 in) |
| — | 3/16" | 15.0 mm (0.59 in) | — |
| 6.0 mm | — | 16.0 mm (0.63 in) | 12.5 mm (0.49 in) |
| 6.35 mm | 1/4" | 16.0 mm (0.63 in) | 13.0 mm (0.51 in) |
| 8.0 mm | 5/16" | 18.0 mm (0.71 in) | — |
| 10.0 mm | 3/8" | 20.0 mm (0.79 in) | — |
| 12.0 mm | 1/2" | 23.0 mm (0.91 in) | — |
| 14.0 mm | — | 23.0 mm (0.91 in) | — |
| 16.0 mm | 5/8" | 24.0 mm (0.94 in) | — |
- Under-Stripped (L < D): Jacket prevents the collet from locking and bypasses the O-ring seal, causing joint blow-off and emergency stops.
- Over-Stripped (L > D + 3.0 mm / 0.12 in): Exposes bare PU tube to flying weld spatter, leading to wall burn-through and line rupture.
Plant Floor Economics & TCO Mitigation
- Protect Line Uptime: Eliminates unexpected tube separation and pressure drops in automated robotic cells, preventing unscheduled maintenance.
- Eliminate Compressed Air Waste: Micro-leaks consume costly utility power (a 1.0 mm / 0.04 in leak at 7 bar / 101.5 PSI spikes operational expenses). Full insertion guarantees positive O-ring sealing to stop air bleed.
- Prevent Workplace Hazards: Prevents burn-through blowouts that trigger dangerous whipping hoses or ignite nearby volatile dusts.
Technical FAQs
Q1. Can tubing be inserted without stripping?
A: No. The outer jacket exceeds standard fitting tolerances. Forcing it into an oversized fitting prevents collet claws from gripping the rigid core, causing pressure blowouts.
Q2. How is minimum bend radius calculated?
A: Strictly by overall outer diameter (O.D.). Maintain 5× to 6× O.D. for dynamic tooling to prevent wall buckling and side-load fatigue on fitting release rings.
Q3. Does stripping leave jacket adhesive residue?
A: No. Adhesive-free co-extrusion allows outer jackets to strip cleanly without sticky film, ensuring an immediate, leak-free inner core seal.